On the August 9th episode of Inkigayo, besides the special girl group stage, we'll also be getting a joint performance of SNSD's Genie, from none other than SHINee's Key and Taemin, and 2PM's Wooyoung and Taecyeon. There's one more person in the group that has yet to be revealed.
Source: 1, 2.
Yes to more SHINeePM. ♥ Keeping my fingers crossed for Jokwon as the 5th person, lol.